The Institute for Laboratory Animal Research (ILAR) develops guidelines and disseminates information on the scientific, technological and ethical use of animals and related biological resources in research, testing and education. ILAR promotes high quality, humane care of animals and the appropriate use of animals and alternatives. ILAR functions within the mission of the National Academies as an adviser to the federal government, the biomedical research community and the public. The goal of this application is to request partial support for an international workshop on science-based guidelines and standards for laboratory animal care. The most effective and valid research on animals relies upon science-based guidelines for their humane care. However, there is a dearth of published information that can serve as the basis for the derivation of guidelines and standards. Consequently, many of the current guidelines, both in the U.S. and abroad are based upon what is considered "best practice" or on anecdotal evidence. In the past several years, there have been more scientific studies on methods of refinement, i.e. those conditions that promote animal well-being and minimize pain and distress. Many of these studies have shown that the state of well-being of experimental animals can have profound effects on experimental outcomes. Yet, in many cases, existing guidelines and standards do not take these data into account. The purpose of the proposed workshop is to bring together experts from around the world to assess the available knowledge that can affect the current and pending guidelines for laboratory animal care, identify gaps in that knowledge in order to encourage future research endeavors, assess the financial and outcome costs of unscientifically-based regulations on facilities and research and determine the potential negative impacts of arbitrary regulations on the animals themselves.